Wn,3(u,ξ)=|ξ|1/2Jν(u|ξ|1/2)s=0n1As(ξ)u2s|ξ|Jν+1(u|ξ|1/2)s=0n2Bs(ξ)u2s+1+|ξ|1/2envJν(u|ξ|1/2)O(1u2n1),